128 CANINE MEDICINE AND SURGERY 



in controlling the severe pains associated with this 

 condition. 



Cataract 



(Opacity of the Crystalline Lens) 



The word "cataract" is applied to any opacity or, 

 want of transparency of the lens, whether partial 

 or complete. It may be congenital or it may occur 

 at any time in the animal's life. It is often pro- 

 duced by wounds of the lens or its capsule, or it may 

 be caused by any disease of the eye that seriously 

 interferes with the nutrition of the lens. It is a dis- 

 ease common to old age, being then caused by im- 

 paired nutrition. 



Treatment. — Only recourse to surgery is of any 

 avail, and in dogs this gives fairly good results, 

 although theoretically it is useless. 



The most practical and successful operation is 

 that of discission, which consists of making a. 

 crucial incision into the anterior capsule of the lens, 

 thus allowing access of the aqueous humor, which 

 first of all causes swelling of the lens, then its 

 absorption. 



The technic is as follows : The patient is anes- 

 thetized, the conjunctival sac washed out with a 

 1-5000 chinosol solution and then with sterile water, 

 and the pupil dilated to its full extent with atropin 

 (if H-M-C is used as the anesthetic, this will be 

 unnecessary). The eyelids are then held apart with 

 an eye speculum, and the discission needle intro- 

 duced through the cornea at its lower median peri- 

 phery. When the needle reaches the anterior cau- 

 sule it is drawn across it twice in a crucial manner 

 and slowly and gently withdrawn. Absorption takes 

 place in about three months. The after-treatment 

 consists in keeping the patient in a darkened kennel 



